A recommendation from the ITU-T covering high-quality coding of audio material at 384 kbit/s. In the same family, we find the J.42, the J.43, and the J.44 recommendations that define the coding of analogue “medium quality” sound at 384 kbit/s, “high quality” sound at 320 kbit/s, and “medium quality” sound at 320 kbit/s, respectively.